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Monday, March 26, 2012

Swans, black and white

Here, in UCD, our lake houses 2 swans (He,
a Cob and She, a Pen). They are white and often, as I pass them, I think of the
philosophy of science, and I will explain the link. How do we know something is
true?

That the sun rises in the east is a given.
It happens every day since time immemorial and thus we can expect it to do so
forever. It is a truth. That the truth is defined as something that can be seen
time after time, was challenged by Karl Popper an Austrian philosopher. He
argued that the truth was best observed from an opposite viewpoint. We do not
attempt to show something to be true by means of endless philosophical
machinations but rather we can show something to be false. No matter how often
the sun rises in the east, we cannot be certain that, one day it will rise in
the southeast or east-southeast and so on. However, if ever the sun rose in the
east-southeast we could say for absolute certainty that the sun does not always
rise in the east. The usual metaphor is the theory that all swans are white.
They always have been and they always will be. And then, some explorers on
Captain Cook’s antipodean expedition discovered black swans. Thus, according to
Popper, the white swan theory was abolished instantly. He saw science
progressing in a cycle of conjecture (‘all swans are white”) and refutation
(‘we just found some black swans’). That all sounds fine until one reads the works of an American
philosopher, Thomas Kuhn. He argues that science existed at two levels. There
was ‘normal science’ and ‘revolutionary’ science. Kuhn regarded the latter as a
paradigm shift, a phrase often repeated since.

We used to believe that all swans are
white but now we know better. Popper and Kuhn seem to be together at this
point. However, whereas Popper believed that this was normal in science, Kuhn
argues that this was not in fact normal. It was revolutionary. Kuhn believed
that most science fell into this classification of ‘normal science, which was
the opposite of revolutionary. Normal science simply defended conventional
wisdom. In fact it vigorously defended it. Let us go back to the issue of ‘all
swans are white”. The explorers, excited by their discovery, decide to write a
scientific paper for the International Journal of Swan Science. The editor
sends it out for review and both reviewers reject it, absolutely. One argues
that these are not in fact swans at all although they might look like swans.
The researchers are asked to conduct extensive genetic sequencing and to
re-submit the paper if that is still justifiable. The second referee goes
further and argues that indeed they may be swans but they are mutants arising
from some pre-mobile phone mast radiation and that they will die off.
Basically, the two naïve explorers thought that science was interested in new
ideas. It is, provided that the sacred central theory is not challenged. And in
this instance, the sacred theory of ‘all swans are white” was not about to be
dumped on the basis of some unknown swanologists out in the antipodes. Careers
and egos are built on the central dogma and upstart wannabe swanologists should
respect that.

Kuhn is correct. Most scientific research
is simply filling in gaps of our knowledge in relation to some large paradigm. Up
until 10 years ago, we believed in the Central Dogma of Biology, that there was
one gene for every protein. With the sequencing of the human genome, we now know
that this is not true. That was revolutionary science. Now we populate our
scientific papers with explanations of how it all works. That is normal science.

Challenging conventional wisdom is laden
with risk to those who would dare to do so. It is not simply that your scientific
papers might be rejected. You, yourself, may be pilloried. A classic case is
that of Bjørn Lomborg, a Danish statistician who wrote a magnificent work: “The
Skeptical Environmentalist”. For his sins he was castigated by the high priests
of global warming and suffered disgrace by the relevant Danish scientific integrity
watchdog, only to be re-habilitated by his own resolute pursuit of the truth. He
now heads a highly prestigious global think tank The Copenhagen Consensus
Center. Lomborg simply challenged the way that environmentalists express their
concerns. For example, one leading pro-environmental NGO pointed out the
spiraling costs of storm damage in the coastal regions of southeast USA. Year
on year the economic impact grew and thus, the conclusion was that year on year,
the weather was getting worse and storms were becoming more frequent and more
severe. All Lomborg did was to show that the value of real estate in this
region was growing year by year and moreover, the number of properties per
hectare was also growing annually. When he adjusted for the value of properties
per hectare, the effect was to show no increase. This is just one of many
examples of his challenge to conventional wisdom. In human nutrition, there are
many sacred tenets: “Breast is best”, “Obesity is the fault of an irresponsible
food industry”, “ The large bowel colonic microflora are central to human health’
etc. To challenge any of these is not easy. To do so labels one as an agenda laden crank who sees
everything in a negative fashion. However, dissent is the oxygen of science and
whereas as dogmatism may be suitable for religious and scientific movements, it
has no place in science. The outlier is often more revealing that the mean.

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"Ever seen a fat fox ~ Human obesity explored"

About Me

I graduated from University College Dublin in 1971 with an Masters in Agricultural Chemistry, took a PhD at Sydney University in 1976 and joined the University of Southampton Medical School as a lecturer in human nutrition in 1977. In 1984 I returned to Ireland to take up a post at the Department of Clinical Medicine Trinity College Dublin and was appointed as professor of human nutrition. In 2006 I left Trinity and moved to University College Dublin as Director of the UCD Institute of Food and Health. I am a former President of the Nutrition Society and I've served on several EU and UN committees on nutrition and Health. I have published over 350+ peer reviewed scientific papers in Public Health Nutrition and Molecular Nutrition and am principal investigator on several national and EU projects (www.ucd.ie/jingo; www.food4me.org). My popular books are "Something to chew on ~ challenging controversies in human nutrition" and "Ever seen a fat fox: human obesity explored"